As a light-emitting material used for a light-emitting layer of a light-emitting device, a composition prepared by doping a phosphorescent light-emitting compound exhibiting light emission from a triplet excited state as a dopant in a host material, is known.
As the host material for a green phosphorescent light-emitting compound, a copolymer (polymer compound) that comprises a fluorene-2,7-diyl group and a 1,4-phenylene group having a specific substituent at a 2-position and a 5-position, is known (Patent Literature 1).